Start here

Use the model to solve the first problem. Then try these quick review questions from earlier lessons.

1. 1

   Same stepsFinish what the group started. Use the model above, step for step. 🔊 Listen 💡 Hint

   Try it together — then prove it:

   1. Find 40% of 80.
   2. What number matches 100% in the first column? (80)
   3. Divide both by 5. What is 20% of 80? (16)
   4. What do you multiply 20% by to reach 40%? (× 2)
   5. Do the same to the other row. What is 40% of 80? (32)
   6. Why must 40% of 80 be less than 80? (100% matches 80. 40% is less than 100%, so its part is less than 80.)

   Show your work
2. 2

   Quick reviewWhich benchmark percent is closest to 9%? 🔊 Listen 💡 Hint

   1. A1%
   2. B10%
   3. C25%
   4. D50%

   How do you know?
3. 3

   Quick reviewEstimate 24% of 80 using a benchmark percent. 🔊 Listen 💡 Hint

   1. Aabout 8
   2. Babout 20
   3. Cabout 24
   4. Dabout 40

   How do you know?
4. 4

   Quick reviewA jacket costs $39.75. Estimate a 20% discount. 🔊 Listen 💡 Hint

   1. Aabout $2
   2. Babout $4
   3. Cabout $8
   4. Dabout $20

   How do you know?

Try these on your own

Choose an answer. Then explain how you know.

1. 5

   Think it throughWhat is 12% written as a decimal? 🔊 Listen 💡 Hint

   1. A0.012
   2. B0.12
   3. C1.2
   4. D12

   Why is that the answer?
2. 6

   Think it throughWhat is 12% of 1,500 tickets? 🔊 Listen 💡 Hint

   1. A1.8
   2. B18
   3. C180
   4. D1,800

   How do you know? Give a second reason as well.
3. 7

   Think it throughCheck with a benchmark: what is 10% of 1,500? 🔊 Listen 💡 Hint

   1. A1.5
   2. B15
   3. C100
   4. D150

   Explain your thinking. What would have to change for a different choice to be right?
4. 8

   Back to the modelWhat steps do you follow every time you find the percent of a number? 🔊 Listen 💡 Hint

Use the words

Fill each blank with a word from the bank.

• A number out of 100 is a ___.
• The whole amount you start with, right after the word “of,” is the ___.
• The amount you get out of the whole is the ___.
• A number sentence with an equal sign, like part = percent × base, is an ___.

Explain the thinking

1. 9

   Find the mistakeRead the mistake. Explain what went wrong, then show the correct step. 🔊 Listen 💡 Hint

   The mistake: A common mistake in Find the Percent of a Number is multiplying by the percent number itself instead of its decimal form — for example, finding 30% of 80 by computing 30 × 80 = 2,400 instead of 0.
2. 10

   Say moreWhat steps did you follow every time to find the percent of a number in the discount table? 🔊 Listen 💡 Hint
3. 11

   Write your ownWrite your own problem about this situation, then solve it and show the answer. The situation: Five phone battery icons are lined up in order. The first is full at 5 bars out of 5, and each one after it has one fewer bar. The last icon has 1 bar left, and the caption says about 1 hour remains. 🔊 Listen 💡 Hint

   Show your work

Last check

These two come from Lesson 4.3. If they are shaky, that is the lesson to revisit — not this one.

1. 12

   Show what you knowExplain your thinking — What is 45% of 360? 🔊 Listen 💡 Hint

   1. A45
   2. B162
   3. C180
   4. D315

   Explain your choice.
2. 13

   From Lesson 4.3Explain your thinking — Estimate 19% of 412 using benchmarks or compatible numbers. 🔊 Listen 💡 Hint

   1. AAbout 8
   2. BAbout 40
   3. CAbout 80
   4. DAbout 200

   How do you know?
3. 14

   From Lesson 4.3Photos take up 3.5 of the 4 GB of used storage. About what percent of the used storage is photos? 🔊 Listen 💡 Hint

   1. AAbout 35%
   2. BAbout 58%
   3. CAbout 87%
   4. DAbout 99%

   How do you know?

Check your progress

Choose the box that best describes how you feel about each skill.